Improve Homebrew installation from landing page

[mae616]

Sanity checks

• [X] I have searched github.com/withfig/fig/issues and there are no duplicates of my issue
• [X] I have run fig doctor in the affected terminal session
• [X] I have run fig restart and tested again (tell us if that fixed it)

Issue Details

Description:

I tried to install fig. https://fig.io/ has a command brew install fig I ran it. I expected Fig to work, but it did not. After that, I did not know what to do next because there was no explanation on the Webpage.

I saw on https://github.com/withfig/autocomplete that 'NOTE: Once it's downloaded, launch the app to set up Fig!' I ran open /Applications/Fig.app/ and added permission to Fig via "Accessibility > Fig". Then Fig worked. it will be more helpful If this instruction appears on the https://fig.io/ also

Environment

MacOS Monterey 12.4  
fig_cli 1.4.7

[clo4]

Agreed, this would definitely help to have on the home page

@mschrage does homebrew allow us to run a command after install? IMO the best solution would be to have it run /usr/bin/open /Applications/Fig.app instead of adding additional instructions, but it'd be very homebrew-like to disallow this. May also be missing a good reason why that would be a horrible idea 😅